What if the only two choices are both pro-creepy spying?
That's why the primary elections are important - by the time we get down to the final two choices, they usually are both in favour of all kinds of evil things. But in the primaries in 2016, we'll probably have 10 choices from each major party, and it's much more likely you'll find someone that matches your views.
It's very important to vote in the primary elections in order to not end up with two evils by the main presidential election. The same logic goes for all other elections, too: your state government, and all levels really. Voting for just one president from two choices is hardly voting at all.
You have a point that it may be difficult to vote for the right people, but it's very easy to make a good start. If a politician campaigns on and promises to increase the amount of creepy spying in your country like Obama did between 2006 and 2008, don't vote for him/her.